A new species of Bryconops (Ostariophysi: Characiformes: Characidae) from the upper rio Tocantins drainage, Brazil

Tharles L O Guedes,Everton F Oliveira,Paulo H F Lucinda

doi:10.1590/1982-0224-20150176

Tharles L O Guedes, Everton F Oliveira + Show 1 more

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https://doi.org/10.1590/1982-0224-20150176

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Abstract

ABSTRACT A new species of the genus Bryconops , subgenus Bryconops , is described from the rio Conceição, a tributary to the rio Palma, upper rio Tocantins drainage, Tocantins State, Brazil. The new species is distinguished from all its congeners, except B. humeralis and B. vibex by the color pattern in vivo (dorsal, adipose, and caudal fins entirely orange). The new species is easily distinguished from B. humeralis and B. vibex by the absence of a humeral spot and by the lack of maxillary teeth (vs . presence of a single humeral spot and presence of 1-3 maxillary teeth on both sides). Furthermore, the new species is distinguished from B. vibex by the number of perforated lateral line scales (38-41 vs. 44-46).

Highlights

Material and MethodsBryconops Kner, a genus of the characiform family Characidae, comprises 20 valid species of small characids distributed across a major portion of South America through the Orinoco, Amazon, Tocantins-Araguaia, Paraná-Paraguay, and São Francisco river basins to many of the smaller river systems of the Atlantic versant from the Essequibo to Oyapock (Lima et al, 2003; Chernoff & Machado-Allison, 2005; Wingert & Malabarba, 2011; Silva-Oliveira et al, 2015)
Two character states exhibited by Bryconops tocantinensis allow its recognition as a member of the genus Bryconops, namely: (1) the presence of a welldeveloped infraorbital sensory canal on the antorbital, and (2) supraorbital sensory canal extending onto nuchal scales
In Bryconops tocantinensis the distal tip of maxilla does not reach the quadrate socket of the articular

Summary

Introduction

Material and MethodsBryconops Kner, a genus of the characiform family Characidae, comprises 20 valid species of small characids distributed across a major portion of South America through the Orinoco, Amazon, Tocantins-Araguaia, Paraná-Paraguay, and São Francisco river basins to many of the smaller river systems of the Atlantic versant from the Essequibo to Oyapock (Lima et al, 2003; Chernoff & Machado-Allison, 2005; Wingert & Malabarba, 2011; Silva-Oliveira et al, 2015). Counts of teeth (except maxillary teeth) and tooth cusps, gill rakers on the first gill arch, vertebrae, supraneurals, and procurrent caudal-fin rays were obtained only from c&s specimens. Bryconops tocantinensis is distinguished from all species of genus Bryconops, except B. humeralis Machado-Allison, Chernoff & Buckup and B. vibex Machado-Allison, Chernoff & Buckup by the color pattern in vivo (dorsal, adipose, and caudal fins entirely orange).

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